Recent technological advancements have led to the development of cardiac troponin assays, namely high-sensitivity cardiac troponin, with drastically increased accuracy allowing for precise detection and quantification of cardiomyocyte injury.1-3 Compared to conventional assays the use of high-sensitivity cardiac troponin assays have revolutionised the evaluation of patients presenting to the emergency department with chest pain in recent years.1,4
Overall, high-sensitivity cardiac troponin assays are valuable tools for accurate diagnosis and efficient management of patients with chest pain in the emergency department and recommended by international guidelines.4-7 In addition, due to their analytical sensitivity (high-sensitivity), troponin is now a continuous variable which can be used for short and long-term cardiovascular risk assessment.8,9
Rapid algorithms allow for safe and fast rule-out of acute myocardial infarction
High-sensitivity cardiac troponin assays allow for rapid risk-stratification of patients compared to previous assay generations.10 Several large, randomised control trials have validated the safety and efficacy of high-sensitivity assays in rapid rule in/out algorithms, i.e. the European Society of Cardiology 0/1h or 0/2h algorithm.10-16 Real-life implementation studies have shown that instituting rapid algorithms using high-sensitivity assays into clinical practice is safe and highly efficacious in identifying patients at low risk for acute MI.17-19 Rapid algorithms thereby help to reduce overcrowding in the emergency department, lower costs, and bring less diagnostic uncertainty for patients.20-22
Application of single sample rule-out in acute myocardial infarction
Recent evidence showed that for patients with very low concentrations of troponin at presentation (e.g. below limit of detection or quantification), a single-sample rule-out approach can identify patients with low risk of acute MI.23,24 Such single-sample rule out approaches have shown excellent sensitivity and negative predictive value for the rule-out of acute MI.23-26 Single sample approaches have recently been recommended in the 2021 American Heart Association/American College of Cardiology guidelines for patients with a normal echocardiogram and symptoms onset at least three hours prior to arrival at the emergency department.6,27 However, caution should be exercised when applying the single-sample rule-out approach to early presenters and late presenters. Early presenters require the use of the serial 0/1 or 0/2-hour protocol instead, while late presenters may require additional evaluation due to the possibility of presenting late in the disease process.23,27
Future opportunities for improved acute myocardial infarction risk stratification
Future opportunities should focus on further refining acute MI risk stratification, especially regarding identification of high-risk patients, according to Dr. Sandoval. For example, novel approaches such as artificial intelligence and machine learning algorithms might prove useful to personalise risk assessment.28,29 Furthermore, integration of all the discussed concepts and approaches into point-of-care testing is an area of high interest.